Electric potentials evoked within a living subject are often sensed with electrodes or assemblies of multiple electrodes placed on the surface of a subject's or patient's body. In many clinical applications, the electric potentials acquired by the electrodes are processed, displayed, and/or recorded by instruments located remotely from the body. In such cases, the electrodes or electrode assemblies communicate with the remote instruments through connecting wires and cables of suitable length from the subject to the instrument.
While the foregoing electrodes are frequently designed to be disposable after use on a single subject, the cables and wires are generally intended to be reused multiple times. The electrodes often include terminals, connectors, or similar assemblies by which they can be detachably connected to the wires and/or cables. The contact surfaces at the points of connection may be subject to contamination, corrosion, or the like, they may cause unreliable connections, or degrade the quality of the bioelectric potentials, which are usually of very low voltage levels. The foregoing connections also may be subject to the ingress of fluids and any fluids entering a connector may degrade its performance. Additionally, many electrical connectors include traditional male and female mechanically matable components where at least one side often includes a cavity, recess, or the like. The cavity or recessed mechanical structures may trap biological contaminants making cleaning and sterilization difficult. Such difficulties may be exacerbated if the cable or wire is used on multiple subjects.
In addition to the foregoing, cables and wires leading from the patient to an instrument also present technical challenges regarding signal integrity. The capacitance between the wires of a given cable may present an undesirable electrical loading on the electrodes. Also, when flexed, cables may evoke triboelectric potentials, which may interfere with the signals of interest. Moreover, cables or wire may pick up electromagnetic interference, which may also degrade the signals of interest.
Often, for safety and signal integrity reasons, an instrument which acquires the electrode potentials generally has its inputs electrically isolated from ground, as well as from other circuits which may contact other parts of the subject. However, a long cable may create significant capacitance to ground, as well as to adjacent cables, at least in part defeating that isolation. The foregoing may lead to signal degradation, often in the form or reduced common-mode rejection. This drawback may be exacerbated where electrosurgical and related RF devices are employed in a subject.
Embodiments of the present disclosure seek to overcome some or all of these and other problems.